Rapid color processing

ABSTRACT

THIS DISCLOSURRE RELATES TO IMPROVED REVERSAL COLOR PROCESSING WHICH INCLUDES HARDENING THE COLOR FILM EMULSION SUBSEQUENT TO DEVELOPING THE NEGATIVE IMAGE OF THE FILM. THE IMPROVED PROCESS PERMITS THE USE OF RELATIVELY HIGH TEMPERATURES IN THE STEPS SUBSEQUENT TO THE HARDENING STEP THUS PERMITTING MORE RAPID FILM PROCESSING WHILE MAINTAINING GOOD COLOR PROPERTIES. THE PROCESS STEPS INCLUDE FIRST DEVELOPING THE NEGATIVE IMAGE, SUBSEQUENTLY HARDENING THE EMULSION TO BE STABLE TO WATER AT 140*F. OR ABOVE, AND THEN COMPLETING PROCESSING WITH STEPS SUCH AS COLOR DEVELOPING, FIXING AND STABILIZING AT ELEVATED TEMPERATURES.

March 6, 1973 D. 1. FoRsT 3,719,493

RAPID COLOR PRocEsslNG Filed March 24, 1971 3 Sheets-Sheet l EXlTPROCESSED A PORT FILM 2 VENT 36 COVER 34 9 L'SER 7 FLM 3 0 2 C 0 E Om 5TN mw mm mm RM M m F my n vw w A mmNjSw T3 O 1/ E Rm O m mm T5 J NN. IwSSWR O O m w m5 2 D SE S PR l QN I. m HMM .N\ 6. M @z x mmm mNjw mm mmm MO/vmss mm ETR ...l D m -(wwi $125@ f O XQ m l b @z Rs wwrzm m nm4 m mw@Q AwHwOzid @z QM. N- .wi Iw mNjSmz m m; wo Rzmswd mzmmd mi NQ 5.60 E Nimmm mNzSmz T2 T|- EDH I. m n OPm L O ,n mZmQwI R m A E mm b mg 55 mmm .wmnd ETR M M b .OQ 5mi j C nd m 5mi O E m4 m5/ O/ M i0 m m0 m CO E0 lo. OC5 O MPR WR n C] l @Dn O PR SE F. OM E4 RM SF. RNL NL l RL NL PH NL3 MmmWU. Ll WH Mmm NF mm5 ETR R U TR U TR UNPROCESSED March 6, 1973 D. J.PORST 3,719,493

RAPID COLOR PROCESSING 3 Sheets-Sheet 2 Filed March 24, 1971 y=1.9(cyan) y 1.9 (magenta) y 2.5 (yellow) Log Exposure- DONALD J. FORSTINVENTOR ATTORNEY March 6, 1973 D. J. FoRs'r 3,719,493

vRAPID COLOR PROCESSING Filed llarch 24, 1971 3 Shoots-Shut 5 STEP NO.\

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RELATIVE LOG EXPOSURE DONALD J. FORST- INVENTOIL BY gamm ATTORNEY.

United States Patent O 3,719,493 RAPID COLOR PROCESSING Donald I. Forst,Webster, N.H., assignor to Itek Corporation, Lexington, Mass.Continuation-impart of applications Ser. No. 699,576, Jan. 22, 1968, andSer. No. 831,226, June 6, 1969, both now abandoned. This applicationMar. 24, 1971, Ser. No.

Int. Cl. G03c 7/ 00 U.S. Cl. 96--55 41 Claims ABSTRACT OF THE DISCLOSUREThis disclosure relates to improved reversal color processing whichincludes hardening the color film emulsion subsequent to developing thenegative image of the film. The improved process permits the use ofrelatively high temperatures in the steps subsequent to the hardeningstep thus permitting more rapid film processing while maintaining goodcolor properties. The process steps include first developing thenegative image, subsequently hardening the emulsion to be stable towater at 140 F. or above, and then completing processing with steps suchas color developing, fixing and stabilizing at elevated temperatures.

Also described are improved processing steps for negative colorprocessing and compositions useful therefor.

Improved silver negative development is realized by use ofmethylhydroquinone. Acidication of the film emulsion subsequent tonegative development is enhanced by swellsuppressing agents. The use ofchelating agents in the stabilizing step substantially eliminates sludgeformation. A fiixing solution containing soluble thiocyanates andsoluble thiosulfates gives improved results. The use of one or moreviscous solutions to improve processing is described.

Apparatus for accomplishing the improved color processing is alsodescribed.

The invention herein described was made in the course of or under acontract or subcontract thereunder with the United States Government,Department of Defense.

CROSS REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part of Forst, Ser. No. 699,576, filed Jan. 22, 1968 andForst, Ser. No. 831,- 226, filed I une 6, 1969, both abandoned.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates to rapid, reversal and negative color processing.

(2) Description of the prior art Many attempts have been made to reducethe time required for processing of multilayer, multicolor photographicelements to positive color images, i.e. reversal color processing, or tonegative color images, i.e. negative color processing. In reversal colorprocessing, the processing steps include first developing to form anegative black and white image; the photographic element is then foggedor re-exposed and color-developed with a color-forming coupler whichreacts with the oxidized developer to form an appropriate dye imagecorresponding to the positive silver image formed. Finally the silverimages and remaining lsilver halide are removed by bleaching and fixingto leave the color image. In negative color processing, the processingsteps involve color developing the exposed film, followed by bleachingout of the silver image, and fixing of the silver halide to leave thecolor image.

Typical prior art color processes wherein first development is carriedout prior to a hardening step are known as 3,719,493 Patented Mar. 6,1973 lCC the Kodak Color Process C-22 (negative) and the KodakEktachrome Process E-l (reversal). These processes are well known andhave been described in numerous Kodak technical publications as well asin Eaton, Photographic Chemistry, 2nd ed., 1965 at page 92 et seq. Thesteps subsequent to hardening in these processes are carried out attemperatures of about F., and these processes take around 60 minutes tocomplete.

A newer reversal process, the Kodak ME-4 process, uses highertemperatures to reduce total processing time. In this process, however,there is no hardening step after first development. Also, this processuses processing temperatures of about F. so that the color properties ofthe processed image will not be harmed by higher ternperatures. Totalprocessing time is approximately 27 minutes.

The attempts to reduce the overall processing time required haveresulted in rapid processing methods which, however, sacrifice colorbalance and soften film emulsion, i.e. lower lm abrasion resistance, inparticular. A solution to the problem of film abrasion resistance hasbeen suggested by the use of hardening agents for the film emulsions,for example as described in U.S. Pat. 3,168,400 to Blackmer et al. Inthe said patent, the film emulsion is subjected to treatment with anaqueous solution of an aldehyde prior to photographic development butsubsequent to photoexposure. However, the prehardening leads toconsiderable difficulty in maintenance of color balance. A majordifficulty in processing color emulsions is the problem of maintainingthe sensitometric characteristics during the first stage of development.Major gamma and speed shifts in one or more of the emulsion layers canalter the color balance. Such alterations are related to the chemicaland diffusion rates of development within each layer. Another effect ofaccelerated development is the softening of the emulsions as a result ofthe use of elevated temperatures and high pH often associated with highenergy developers. The hardeners are used to reduce these effects.However, the hardeners normally harden the top layer (the yellow dyeforming layer in Ektachrome film) to a greater degree than the secondand subsequent layers (the magenta and cyan layers). Thus, when the filmis immersed in the rst developer, reaction on the rst layer is not asfast as that on the subsequent layers. This generally causes severeshifts in gamma and speed, and tends to alter the color balance. Suchalteration cannot be wholly compensated for in the remaining stages ofthe process since the original sensitometric characteristics have beenaltered.

Generally, the maximum temperatures heretofore utilized in the variousprocessing steps do not substantially exceed 100 F. and usually aresomewhat lower than 100 F. since the use of high temperatures,particularly with significant changes of pH in the various steps, leadsto rapid change in the swell of the lm emulsion, particularly gelatinwhich is most common in lm. As is commonly known, gelatin swell leads toimage distortion.

A further diiiculty encountered in reversal color processing is the needfor numerous water washing steps because of water volume requirementswhich, in automated processing apparatus, creates the need foradditional baths in the processing sequence, and results in more complexand larger apparatus. Most attempts to reduce the processing time havebeen directed to elimination of large volumes of wash water which havebeen only partially, if at all, successful.

SUMMARY OF THE INVENTION It has now been unexpectedly found that rapidcolor processing can be accomplished by first developing the negativeimage in a multilayer film and subsequently rendering the film stable toWater at a temperature of at least about 140 F., followed by the usualprocessing. 'Ihis sequence of steps avoids the difiiculties inherent infirst hardening the film emulsion prior to negative development.Specifically, better color balance is obtained since the sensitometriccharacteristics of the various emulsion layers of the film are moreeasily controlled than is possible with emulsions which are prehardened.However, one skilled in the art will recognize that a limited amount ofhardening prior to first development is permissible, either in theprocessing or in the manufacture of the film, so long as thisprehardening does not substantially interfere with the color balance andcreate other above mentioned problems in the color processing.

After the development of the negative image, the film emulsion isrendered stable to water at a temperature of at least about 140 F., andpreferably at least about 180 F., when rapid, h'igh temperature colorprocessing is desired. The upper limit of temperature to which thehardened film is stable is limited only by the boiling temperature ofthe treating solution, i.e. for practical considerations, about 212 F.

For the purpose of this disclosure, the word stable means that the filmemulsion undergoes no change adverse to photographic processing.v Suchchanges primarily include softening of the film emulsion, which leads todistortion of the color image, and film reticulation, the mostpronounced effect of which is separation of the film emulsion from thesupport material.

In its preferred form, the invention contemplates the use of aldehydehardeners, especially dialdehyde hardeners.

Although it is preferred to stabilize the film subsequent to firstdevelopment, it `will be understood that the stabilizing step may beused at any point in the subsequent processing of the film, e.g.,subsequent to the color developing step in reversal color processing.The stabilization subsequent to the first development is preferred sinceit permits shorter processing time in each of the subsequent steps byallowing the use of higher temperatures than are normally employed.

For the purpose of this disclosure, the term rapid processing orhigh-speed processing refers to processing wherein at least one, andpreferably several or all, of the steps subsequent to hardening arecarried out at a temperature in excess of 100 F., usually above 110 F.,and `wherein total processing time is not more than about 30 minutes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a deep tankcontinuous processor for rapidly processing color-reversal film.

FIG. 2 illustrates a deep tank continuous processor for rapidlyprocessing negative color film.

FIG. 3 illustrates a modified deep tank continuous processor for rapidlyprocessing color-reversal film using a viscous color developer.

FIG. 4 illustrates sensitometric curves for a reversal color lmprocessed according to this invention.

FIG. 5 illustrates sensitometric curves for a negative color filmprocessed according to this invention.

FIG. 6 illustrates sensitometric curves for a negative color lmprocessed according to a prior art method.

REVERSAL COLOR PROCESSING In reversal color processing, the filmemulsion subsequent to the first development step is alkaline andtherefore must be acidified prior to aldehyde hardening to preventreaction of the dye coupler in the film emulsion with the aldehyde. Theefficiency of the acidification step is particularly enhanced by thepresence of swell-suppressing agents in the acid bath. During theacidification process, the excess developer and oxidized developer areremoved from the film emulsion, which removal is also enhanced by theswell-suppressing agents.

After the developed film is acidified, it is then hardened with thealdehyde hardener, after which the excess aldehyde must be removed priorto the color processing since the aldehyde, if present in the film,would react with the color formers, e.g. as described in U.S. Pat.3,168,406.

Once the excess aldehyde has been removed, the film may then becolor-developed, fixed and stabilized, i.e. color processed, usingstandard procedures, such as described in U.S. Pats. 3,232,761 and3,168,400.

The development of the negative silver image, i.e. the firstdevelopment, can be accomplished using standard developer systems inwhich the developer is most cornmonly hydroquinone, but may also beother hydroquinone derivatives or equivalent compounds. Exemplarydevelopers include phenylhydroquinone, chlorohydroquinone,dichlorohydroquinone, tetrachlorohydroquinone, bromohydroquinone andsimilar such organic developers. A particularly effective developer inrapid developing of the negative silver image is methylhydroquinonewhich, in comparison to hydroquinone, provides a much faster combinationwith Metol (methyl-para-aminophenol sulfate) and/or Phenidone(l-phenyl-3-pyrazolidone). A particularly effective combination ismethylhydroquinone and Phenidone which gives fast, efficientdevelopment. For optimum results, methylhydroquinone should be employedat a pH value between 9.5 and 10.5 but preferably at a pH of 10. Thepreferred concentration of methylhydroquinone is from about 4 to about13 grams/liter of developer solution. When methylhydroquinone is usedwith Phenidone, the concentration of Phenidone is preferably from about0.5 to about 6 grams/liter of developer solution.

The developer solution may contain accelerators (such as diamines,catechol, aliphatic amines or quaternary ammonium salts),Water-softener, sodium sulfite as stabilizer, soluble thiocyanates andbuffer (to control the solution to the desired alkaline pH) all of whichare known in the art. The pH of the developer should be sufficientlyalkaline to ionize the developer but not too alkaline to avoid filmemulsion damage.

Where high energy developer systems are employed, anti-fogging agentsare advantageously employed to minimize fogging of the emulsion,particularly in the outer layer. Suitable anti-fogging agents are knownin the art (vide: U.S. Pat. 3,295,976).

The temperature at which the first development should be conducted mustbe limited to just below the minimum film reticulation temperature, i.e.the temperature at which the emulsion undergoes damage. Usually,temperatures at or near room temperature ranging to 75 F. or slightlyhigher may be used with commonly available three layer film.

After the first development, the film is then treated in an acid stopbath for a time sufficient to acidify the emulsion. `If not acidified,the emulsion being alkaline from the first development step, thealdehyde hardner will react with the color couplers in the emulsion andthus reduce the amount of color coupler available for the color-formingdevelopment step. The adjustment of the film emulsion to acid pHprevents such reaction as is known in the art. It has been surprisinglyfound that the use of swell-suppressing agents in the acid stop bathimproves the efiiciency of the acidification, and also facilitatespassage of the undesirable developer and oxidized developer into theacid stop bath.

The swell-suppressing agents include a variety of inorganic compounds,especially soluble sulfate, nitrate and phosphate salts such as alkalimetal or ammonium salts. Especially effective are alkali metal sulfatesor ammonium sulfate. `Of these, sodium sulfate is preferred due to itsready availability. The amount of salt employed usually ranges fromabout 20 g. to about 100` g. per liter of stop bath solution. The amountis not critical as long as sufficient quantity to suppress the filmswelling is employed. Such amount is readily determinable by routinetesting. The aforementioned range will inlud the most commonly effectiveamounts, which amounts of course are dependent on the nature of the filmemulsion. n

The stop bath usually contains an organic acid in an amount to provide apH in the range of about 4 to 6 and may include buffer salts to insuremaintenance of the desired pH value. Most commonly, acetic acid isemployed because of its availability and economy but other` such acidsmay be used, e.g. citric acid, propionic, gluconic, and the like.

The length of time required for exposure of the film to the acid stopbath will vary from two to four minutes, but when the swell-suppressingagent is present, the residence time required is materially shortened,thus minimizing the possible deleterious effect of the acetic acid onthe color materials in the layers of the emulsion. lor example, with theswell-suppressing agents in the acid stop bath, a period of about 30seconds is all that is required to render the film emulsion acidic. Inaddition, it is found that a better maximum density is obtained in thecolor film eventually developed when the swell-suppressing agent isemployed in the acid stop bath.

The aldehyde hardening step is accomplished by immersing the film in ariaqueous solution of the aldehyde hardner at a concentration of at least1%, the actual concentration being determined by the individual aldehydeselected and the degree of hardness required. The hardners are useful inacid or neutral solution, but are preferably used at acid pH values,usually not lower than a pH of 4.

Some aldehydes are not as effective as others, as might be expected. Themost effective are dialdehydes and, especially glutaraldehydes, such asglutaraldehydes, betamethyl-glutaraldehyde; alpha,alpha-dimethylglutaraldehyde, alpha-methylglutaraldehyde, and alpha,beta-dimethylglutaialdehyde. In general, the hardening procedure isknown to the art and has been described in the literature, e.g. U.S.Pats. 3,232,761 and 3,168,400. Other aldehydes may be employed, e.g.succinaldehyde, formaldehyde, and combinations of these.

In the present process it is preferred to treat the film with thealdehyde solution at an initial temperature ranging up to 100 F.although higher temperatures are possible. A particularly preferredtemperature is about 100 F. at which a thirty second treatment providesexcellent results. In this step, the use of higher temperature may leadto emulsion damage if only in the initial immersion. Since at 100 F. aperiod of only 30 seconds provides optimum results, the use of highertemperatures is .not necessary and is avoided particularly because ofpossible deleterious effects to the emulsion.

The film may be processed with the aldehyde hardner immediately afterthe acid stop bath treatment with no intervening washing step.

As has been previously mentioned, the emulsion is treated in thehardening step to make it stable to water at a temperature of at least140 F., and preferably 180 F. This limitation is a measure of the amountof hardening required, and is not intended to specify processingtemperatures for steps subsequent to hardening.

After the hardening step, as previously mentioned, the excess aldehydein the emulsion must be removed before the color processing steps sincecarryover of the aldehyde will result in undesirable side reactions, anddiminish color formation. The aldehyde may be removed by reaction withaldehyde reactive compounds, such as aldehyde-reactive amines by themethod described in U.S. Pat. 3,168,- 400, which is incorporated hereinby reference.

The color developing step is accomplished by art recognized methods anyof which can be employed in the present process.

The subsequent processing steps of bleaching, fixing, and stabilizingcan be done by art-recognized procedures.

A particularly effective fixing solution is one comprising a mixture ofa soluble thiocyanate and a soluble thiosulfate which gives rapid andefficient fixing. The soluble forms of each of the salts embrace theammonium salt and alkali metal salts, especially the sodium salts whichare most readily available and thus preferred. A particularly effectivemixture of the fixing agents is a molar ratio of 1 mole of thiocyanateto 3 moles of thiosulfate, which gives best results.

As is generally known, after bleaching and fixing, the film isstabilized by treatment with known stabilizers, most commonlyformaldehyde. It has been unexpectedly found that the addition ofchelating agents to the stabilizing solution eliminates sludge and scumformation which is often noted in developed color film, particularlywhen processed at higher than room temperature after use of the aldehydehardeners. For example, a formaldehyde stabilizer solution showed heavysludge formation in a short time of use, e.g. after processing about 2square feet of film. The addition of a chelating agent substantiallyprevented sludge formation until the reagent became spent.

The chelating agents are assumed to react with dissolved iron, in theform of Fe(II) and Fe(I`II), and silver ions, solubilizing these in theform of soluble chelate compounds. This assumption is not meant to bebinding but is offered as a possible explanation. rllhe chelating agentsare those which, in fact, do form soluble chelate compounds 'withmetallic ions and include ethylenediaminetetraacetic acid andethylenetriaminepentacetic acid, inorganic salts such as solublephosphates, e.g. tetrasodium pyrophosphate, and organic acids, such asgluconic acid and heptanoic acid. Of course, the chelating agentselected should not react in an adverse wa'y with the film or thestabilizer under the conditions of use, i.e., they should bephotographically-compatible.

The amount of chelating agent can vary substantially and will bedetermined by the needs of any process. In batch treatment methods, moreconcentrated solutions up to the limit of solubility of the chelatingagent would be employed. In automated processing, any convenientconcentration may be maintained by automatic replenishment systems. Therequired concentrations of chelating agent may be determined by routineexperimentation. In replenishment systems, the usual concentration ofchelating agent is approximately from 5 to 20 grams per liter, withabout 10 grams per liter being preferred.

The problem of sludge formation which clogs tanks and lines in automaticprocessing apparatus and necessitates frequent change of stabilizersolution is essentially obviated by the aforementioned use o f chelatingagents. In normal use, the stabilizer remains sludge free and usefuluntil the effective chelating capacity is exhausted.

As previousl'y mentioned, hardening of the emulsion subsequent to silvernegative development is preferably accomplished with dialdehydehardeners, especially a glutaraldehyde hardener which permits the use ofhigher temperatures than previously possible in the various steps ofcolor-processing, i.e. color-developing, stopping the color developer,bleaching, fixing and stabilizing. Temperatures Well in excess of F. canbe employed, ranging up to about 180 F. and even higher. For practicalpurposes, temperatures in the range of from about to about 155 F. arepreferred since these temperatures give optimum results and areespecially suited for automatic `film processing equipment.

As will be appreciated by those in the art, the use of high temperaturespermits more rapid processing since it reduces the time requirements forthe various steps of reversal color processing, thus reducing theoverall time vrequired for processing an exposed color film to a colorimage. For example, when the color-processing steps are conducted at atemperature of F. the total processing time is reduced to as little as 5minutes, or slightly less than 5 minutes.

NEGATIVE COLOR PROCESSING In contrast to reversal color processing,negative color processing involves a first development with a color- 7forming developer in which the negative silver image and color image aresimultaneously formed. The color-forming developers used and the methodsof developing are well-known in the art and are those mentioned inconnection with the color development step of reversal color processing.

For rapid negative processing, the developing step is conducted attemperatures below the minimum lm reticulation temperature. Usually,temperatures at or near room temperature ranging to 75 F. or slightlyhigher may be used with commonly available three layer film. Thedeveloping is stopped as desired by treatment of the developed lm withart-recognized clearing baths, after which the film is then hardened asdescribed herein for color reversal processing.

The hardening treatment and the subsequent processing steps ofbleaching, iixing and stabilizing are accomplished using the sameprocedures as hereinbeforedescribed in connection with the colorreversal processing. However, combination of steps is possible, Forexample, bleaching and fixing can be effected by using a combinedbleachfixing bath which combined bath usually requires from about 45seconds to about 60 seconds. If the hardening step is conducted atalkaline pH, the stabilizing step may be omitted, in which case, thechelating agent normally used in the stabilizer solution can be includedin the fixing solution, even when combined with the bleaching solution.

In general, the procedures, including the temperature and time for thevarious steps of negative color processing are the same as for reversalcolor processing. One exception is the time required for negativedevelopment where usually from about two to about 2.5 minutes isnecessary.

As in reversal color processing, hardening of the color lm prior tonegative development gives the same difculty with color balance sincethe sensitometric quality of the lm is permanently set in the firstdevelopment step.

In some instances, both the rapid reversal color process and the rapidnegative color process described herein can be improved by using one ormore viscous processing solutions. Any number of the liquid processsolutions used for either of these color processes can be made viscousby the addition of small amounts of one or more thickeners.

.lt has been found that the shelf life of color processing solutions,normally very short with liquids because of their complex nature, can bedoubled or improved even more by making them viscous.

Additionally, it is much more economical to use viscous color processingsolutions than their nonviscous counterparts. This is partly because thecomplex formulations can be simplified, as for example by omittingbuffers and using smaller amounts of sulfites which are required inliquids to prevent aerial oxidation of various processing agents. It isalso possible when using viscous solutions in some cases to eliminatecertain processing solution entirely. Washes heretofore used betweenprocessing solutions can be eliminated. Another factor contributing tomake viscous processing solutions more economical than their liquidcounterparts is the fact that more eflcient use of the activeingredients can be accomplished by using just the proper amount of agentin each viscous layer applied to the film. This is not possible, ofcourse, when liquid baths are used to continuously process large volumesof film because such baths require replenishment systems which result inthe Waste of good chemistries through the overiiow.

Other advantages resulting from the use of viscous processing solutionsin contrast to normal liquid solutions include the lower cost ofmaintaining eleveated temperatures of the thin viscous layers for rapidprocessing and the use of less complex and more economical processingequipment made possible by the elimination of the need processing tanks,agitation devices and replenishment systems.

Furthermore, it is possible to process at higher temperatures usingviscous processing solution Without encountering the problems normallyencountered with liquids at elevated temperatures such as lmreticulation and softening of the photosensitive emulsion. Processingtemperatures of up to about 150 F. or more can be used. Higherprocessing temperatures, of course, result in faster processing rateswhich are always welcome in color lm processing.

Additionally, it is not necessary to maintain large volumes of solutionsat high temperatures when viscous solutions are used. This reduces thepower required for operating automatic processing equipment and alsoeliminates many of the other problems associated with having to maintainlarge volumes of photographic processing chemistries at very hightemperatures.

Standard color processing liquids are made viscous by adding one or morespecial thickeners. The term thickeners is used to describe a class ofchemical agents which cause the processing liquids to become veryviscous when small amounts are added. In general, these agents shouldprovide the processing liquids with a viscosity in the range of fromabout 100 to about 50,000 centipoises measured at F. with a viscometersuch as a Brookfield viscometer when an amount of agent of 5% by weightor less based on the total weight is added to the processing liquids.Preferably, amounts of up to about 5% of the agent will provide theprocessing solutions with viscosities in the range of from about 1,000to about 20,000 centipoises measured at 80 F.

Some examples of preferred thickeners because of the good results theyproduce include the following:

C allf. Marine Colloids, Inc., Sllngfleld, N .J

Manueel SA/ LM Sodium alginate derivative.

polystyrene Dow Chemical Co.,

sulfonate. Midland, Mich.

Guaiv bean gum Stein, Hall L Co., Ine.

New York, N.Y.

Polymer 705D As `can be seen, naturally occurring substances such aspolysaccharides and synthetic polymers such as polystyrenes can be usedas thickeners providing they meet the criteria set out above. Many otherthickeners will be known or ascertainable by routine experimentation tothose skilled in the art.

The above discussion is not meant to indicate that all of the thickenersmentioned or all of those known by others can be used in each and everycolor processing solution, or should be used in each and everyprocessing solution. There are several criteria that should be followedin selecting a particular thickener or combination of thickeners for thespecific color processing liquid under consideration. These criteriainclude: nertness over the operative pH range in the presence of theanions and cations in solution; ability of the viscous solution toresist chemical breakdown of the viscous agent due to oxidation orbacterial action; and, good mixing characteristics. These and othercriteria which are well known to those skilled in the art will requireonly routine experimentation to apply before a particular thickener orcombination of thickeners is selected for a specific color processingliquid.

Apparatus for continuously and automatically carrying out the rapidcolor processes described herein is illustrated in FIGS. 1-3.

FIG. l illustrates a deep tank continuous processor suitable forpracticing the rapid reversal color process described herein. Anunprocessed reversal ilm 2, previously exposed, enters the processor byentrance transport roller 4 and is thereafter conveyed by a sequence oftransport rollers 5 and turnaround rollers 9 through a series ofprocessing solutions contained within the various tanks of theprocessor. Processed reversal color film 3 exits from the processor bymeans of exit transport roller 7. The transport rollers 4, 5 and 7 aredriven by suitable means such as a chain drive.

As can be seen, the processor has tanks respectively containing: firstdeveloper 6, stop bath 8, hardener 10, neutralizer 12, color developer14, clearing bath 16, bleach 18, fixing bath 20, wash 22, and stabilizer24. A dryer 26 is provided after stabilizer 24. Suitable solutions foreach of the tanks are described in Example 1. The time of processing foreach of the solutions is determined by the path length of the film ineach tank. The path length can be suitably adjusted by varying thenumber and length of up and down traverses the film makes in each tank.

While the solutions require special materials of construction, these arewell known in the photographic processing art.

Where there is a large temperature differential between adjacent tanks,it is desirable to provide thermally insulated walls between such tanks.In the apparatus shown in FIG. 1, for example, insulated walls 28, 30and 32 are used to respectively separate stop bath 8 from hardener 10;neutralizer 12 from color developer 14; and stabilizer 24 from thedrying section 26.

Since hardening is often accomplished with aldehydes which tend to giveoff noxious vapors, hardener tank 10 is provided with a cover 34 toprevent leakage of these vapors and a vent 36.

FIG. 2 illustrates an apparatus suitable for processing a negative colorfilm using the rapid process described herein. An exposed, unprocessednegative color film 50 is introduced into the apparatus by entrancetransport roller 52 and is subsequently conveyed through a series ofprocessing tanks by transport rollers 53 and turn-around rollers 57. Thelength of time that the film is exposed to each processing solution isdetermined by the number and length of up and down traverses the filmmakes on rollers 53, 57 in each tank. Fully processed negative colorfilm 51 exits from the processor by means of exit transport roller S5.

The processor is divided into a number of tanks containing respectively:color developer 54, clearing bath S6, hardener 58, bleach 60, fixingbath 62, Wash 64, and stabilizer 66. A dryer 68 ris provided afterstabilizer 66. Suitable processing solutions can be found in Example 7.The respective tanks require special materials of construction becauseof the corrosive chemicals contained in many of these solutions, butthese are well known to those skilled in the photographic processingart.

Where a significant temperature differential exists bctween adjacentprocessing solutions, the apparatus is provided with thermally insulatedwalls therebetween such as walls 70 and 72 separating the clearing bath56 from the hardening bath 58 and the stabilizer 66 from the dryingsection 68.

FIG. 3 illustrates another embodiment of a processing apparatus forrapidly procesing reversal color film by a modified process as describedherein. Unprocessed, exposed reversal color film 100 is introduced tothe processor by entrance transport roller 101. The fully processed film102 exits from the machine by means of exit transport roller 103. In theapparatus, the partially processed film is transported through a seriesof tanks containing the required processing solutions by transportrollers 104 and turn-around rollers 105.

The processor is divided into a series of tanks respectively containing:first developer 106, stop bath 108, hardener 110, neutralizer 112, colordeveloper 114, water wash 116, clearing bath 118, bleach 120, fixingbath 122, wash 124, and stabilizer 126. A dryer 128 is provided afterstabilizer 126.

In this apparatus, a viscous color developer solution is used to colordevelop the film rather than the normal color developer. Viscous colordeveloper is extruded onto the exposed film surface by extrusion head130. Color development section 114 of the processing apparatus does notcontain processing solution, of course, but merely contains moist air atan elevated temperature, preferably about 150 F. After a layer ofviscous color developer has been extruded onto the film surface, thefilm passes down towards the bottom of color development section 114 andaround reversing transport roller 132 which flips the film over so thatthe viscous layer remains on the top surface as the film travels backtowards the top of color development section 114. After color processingis complete, viscous color developer is removed from the film in waterwash section 116 by a series of water sprays 134 before the film entersthe next tank containing clearing bath 118.

Processing apparatus using viscous color development has the advantagethat a large tank of color developer does not have to be maintained at ahigh temperature thereby lessening power requirements and simplifyingprocessing.

As should be obvoius to those skilled in the art, the aforementionedimproved acid stop bath for the first developer, i.e. silver negativedeveloper, is useful not only in rapid processing of color reversal filmbut also in normal color processing in general, as is true of thestabilizer solution containing chelating agent, and thesulfate-containing stopbath. The developer solution containingmethylhydroquinone is also useful in normal color processing as well asin processing of black and white film.

Multi-layer films of the type which can be employed in the presentinvention are well known in the art and have been described in thepatent literature, such as U.S. Pats. 2,322,027; 2,252,718; theaforementioned 3,168,400 and 3,232,761; and 3335,004, among others.

The following examples further illustrate the invention.

EXAMPLE l A three-color silver bromoiodide film wherein gelatin isemployed as the hydrophilic colloid and wherein cyan, magenta and yellowcolor formers of the type described in U.S. Pat. 2,322,027, mentionedabove, are incorporated in the emulsions, is exposed for 1750 second toa SOO-watt tungsten lamp, adjusted to a color temperature of 6l00 K. inan intensity scale sensitometer, and then treated in a developer havingthe following composition:

Quadrafos (sodium tetraphosphate-sequestering H2O to make one liter.

The solution is maintained at 75 F. and the total treatment time isseconds.

The developed film is immersed in a `stopbath maintained at F. for aperiod of 30 seconds and having the following composition:

Acetic acid (glacial) ml-- 20 Sodium acetate g-- 10.5 Sodium sulfate g100.0

H2O to make one liter.

Without intervening washing, the film is next treated in a hardeningbath maintained at F. for a period of l0 seconds and having thefollowing compositions:

Glutaraldehyde (25% solution) ....ml-- 80 Sodium sulfate (anhydrous)-g-- 100 H2O to make one liter.

pH adjusted to 4.0.

The hardened film is then immersed in an aldehyde neutralizer bothmaintained at 100 F. for 10 seconds and having the followingcomposition:

4-amino N ethyl-N- (beta-methanesulfonamidoethyl)mtoluidinesesquisulfate monohydrate g 13.0 Sodium hydroxide g 7.5 H2O to make oneliter.

After development, the film is immersed for 10 seconds at 145 F. in aclearing bath composed of sodium metabisulte (40.0 g. per liter ofwater) and then bleached for 40 seconds at 145 F. in a solution composedof:

Potassium ferricyanide g 120 Sodium bromide g 40 Borax g 1 Carbowax(polyethyleneglycol) (50% solution) ml.-- 10 Sodium hydroxide g 3 H2O tomake one liter. pH adjusted to 7.85101.

The film is then fixed by immersion for 25 seconds at 145 F. in a fixingbath composed of:

G. Ammonium thiocyanate 250 Sodium thiosulfate (anhyd.) 150 Sodiumsulfite 20 Boric acid 7.5 Sodium metabisulfite 2O H2O to make one liter.

Finally, the film is stabilized by treatment for 15 seconds at 145 F. ina solution composed of:

Formalin ml 10 Ethylene diaminetetraacetic (tetra sodium salt) g 10 H2Oto make one liter.

The total processing time is 266 seconds. Good sensitometric results areobtained.

EXAMPLE 2 A strip of Ektachrome type 2448 iilm is exposed on an EastmanKodak Ib sensitometer with a Corning 5900 daylight filter, to 21 stepcarbon Wedge for 1/25 second. After exposure the strip is processedaccording to the following sequence:

Developer: 75 F. for 70 seconds Stop bath: 75 F. for 30 secondsHardener: 100 F. for 30 seconds Neutralizer: 100 F. for 10 seconds Colordeveloper: 145 F. for 35 seconds Clear: 145 F. for 10 seconds Bleach:145 F. for 40 seconds Fixer: 145 F. for 25 seconds Rinse: 145 F. for 10seconds Stabilizer: 145 F.. for 15 seconds.

12' Developer:

Quadrafos g 2.0 Phenidone g 1.0 Sodium sulfite (anh.) g 25.0Methylhydroquinone g 7.0 Ethylenediamine (93%) ml 26.0 Sodiumthiocyanate g 1.0 Boric acid g 12.0 Potassium iodide (0.1% soln.) ml13.0 l phenyl-Z-tetrazoline-S-thione (0.5% soln.)

ml-- 5.0 Water to make 1.0 liter. Stop bath:

Sodium sulfate g 100.0 Acetic acid (glacial) ml 20.0 Sodium acetate(3H2O) g 10.5 Water to make 1.0 liter. Hardener:

Glutaraldehyde (25% soln.) ml 80 Sodium sulfate (anh.) g H2O to 1.0liter. pH 4.0. Neutralizer:

Hydroxylamine sulfate g 20.0 Sodium sulfate (anh.) 50.0 Acetic acid(glacial) ml 10.0 H2O to 1.0 liter.

Color developer:

Quadrafos gms 5.0 Benzyl alcohol ml 15.0 tert-Butylamine borane gms 0.28Sodium sulfite (anh.) gms-- 7.5 Sodium phosphate (tribasic) gms 40.0Sodium bromide gms 0.9 Potassium iodide (0.1%) ml 31.0 Citrazinic acidgms.-- 3.6 4 amino-N-ethyl-N-(betamethanesulfonamidoethyl) m toluidine',sesquisulfate monohydrate gms. 13.0 'Sodium hydroxide gms. 7.5 H2O to1.0 liter. pH 12.0.

Clearing bath:

Potassium metabisulfite gms 40.0 H2O to 1.0. liter.

Bleach:

Sodium bromide gms 26.0 Sodium ferrocyanide (10H20) gms 180.0 Potassiumpersulfate gms- 51.0 Sodium phosphate (dibasic anh.) gms 12.5 Carbowax1540 (50%) ml 6.0 H2O to 1.0 liter. pH 7.8.

Fixer:

Sodium sulfite g l0 Sodium thiosulfate (SHZO) g 250 Ammonium sulfate g50 Stabilizer:

Formalin solution ml 10 Ethylenediamine tetraaceticacid (tetra sodiumsalt) g 10.0

Water to make 1.0 liter.

Good sensitometric results are obtained, as evidenced by the good colorbalance as shown in the sensitometric curves of FIG. 4.

EXAMPLE 3 A strip of Ektachrome 2448 exposed as described in Example 2is processed similarly except that in place of methylhydroquinone anequal molar concentration of hydroquinone was used (6.2 grams/l). Thesensitometric results indicate that photographic speed decreased 50% (1f stop) for all three dyes; a 25% increase of development time isrequired to restore the speed.

EXAMPLE 4 A strip of Ektachrome type SO-271 is exposed as in Example 2for l/m second and processed as in Example 2 except the stop bath didnot contain sodium sulfate. The maximum density obtained with magentadye decreased 0.3 density units.

EXAMPLE 5 A strip of exposed Ektachrome type SO-271 is hardened andneutralized prior to the first developer (prehardened) which is followedby the stop bath, color developer, and the remainder of the process inExample 2. Because of the silver halide fogging property of aldehydehardeners the sensitometric results indicates serious dye densitylosses. The addition of two antifogging agents: 3 rng./l.I1-phenyl-Z-tetrazoline-5-thione and 20 ml./l. N-methyl benzothiazoliump-toluene sulfonate to the hardener and the addition of 17 gm./1. sodiumbromide to the neutralizer restored the dye densities. However, colorbalance is seriously modified, as evidenced by lack of good colorbalance. Attempts to restore proper color balance by varying the firstdeveloper time are unsuccessful.

EXAMPLE 6 The procedure of Example 2 is repeated except the stabilizerdoes not contain E.D.T.A. 4 Na. After several strips have beenprocessed, a precipitate and a colloidal suspension formed in thestabilizer. A11 strips upon drying form a scum on the surfaces of thefilm. This does not occur when EDTA 4 Na is present in the stabilizer.

EXAMPLE 7 A strip of Ektacolor Print film is exposed on an Eastman Koday1B sensitometer to a 21 step carbon wedge for 1 second with filtrationto obtain a neutral image (.20 magenta-l-.SO yellow-i-WrattenZB-I-Kodacolor Negative mask). After exposure the film is processedaccording to the following schedule:

Developer: 75 F. for 3 minutes Clear: 75 F. for 30 seconds Hardener: 100F. for 30 seconds Bleach: 150 F. for 30 seconds Fixer: 150 F. for 25seconds Rinse: 150 F. for 10 seconds Stabilizer: 150 F. for l5 secondsDeveloper:

Benzyl alcohol ml-.. 9.0 Benzotriazole g `0.05 o-nitrobenzamidazolenitrate g-- 0.05 Sodium sullite (anh.) g-- 2.5 4amino-N-ethyl-N-(betamethanesulfonamidoethyl) m toluidine sesquisulfatemonohyhydrate g 12.0 Sodium metaborate g-.. 40.0 Sodium phosphatetribasic g 20.0 Potassium bromide g 1.2 Sodium hydroxide g-.. 4.0 pH11.7.

Clear:

Potassium metabisulte g 80.0 H2O to 1.0 liter.

The remaining solutions are identical to those for re- 'versalprocessing described in Example 2. Good sensitometric results areobtained as shown in FIG. 5.

EXAMPLE 8 The procedure of Example 7 is repeated except that thedeveloping is carried out at 100 F. lfor 1 minute and clearing at 100 F.for 30 seconds. Good sensitometric results are obtained. However,emulsion reticulation occurs.

EXAMPLE 9 The procedure of Example 7 is repeated except the hardeningstep precedes the development step, according to the following schedule:

Hardener: F. for 30 seconds Neutralizer: 100 F. for 10 secondsDeveloper: F. for 30 seconds Clear: 150 F. for 10 seconds Bleach: 150 F.for 30 seconds Fixer: 150 F. for 25 seconds Rinse: 150 F. for 10 secondsStabilizer: 150 F. for 15 seconds The results indicate serious foggingof the magenta and yellow layer, while underdevelopment of the yellowlayer also occurs. The addition of organic antifoggants to the hardener(3 mg./l. 1-phenyl-2-tetrazoline-S-thione and 20 mg./l. N-methylbenzothiazolium p-toluene sulfonate) reduces the fog level considerably.However, the sensitometric results shown in FIG. 6 indicate a stillexcessive fog level for magenta and very serious underdevelopment of theyellow layer. Further attempts to restore good color balance when thehardener is used prior to development are equally unsuccessful.

EXAMPLE 10 The procedure of Example 2 is repeated withdiethylenetriamine pentacetic acid, in lieu of ethylenediaminetetraacetic acid with similar results. Similarly tetrasodiumpyrophosphate, gluconic acid and heptanoic acid are substituted forethylenediamine tetracetic acid with similar results.

EXAMPLE l1 The following rapid reversal color process solutions areprepared by first preparing the processing liquid and then mixing in thespecified thickeners until the solution is viscous and homogeneous:

First developer:

Sodium sulte g 75 EDTA g 2 Phem'done g 1 Hydroquinone g-- 30 Sodiumhydroxide g.. 25 Thymol1 ml-- 5 H2O to 1 liter. Kelzan F (thickener) g--5 Manucol SA/LM (thickener) g-.. 25

Viscosity 12,600 centipoises. pH 12.5.

First stop bath:

Thymol 1 ml 5 Sodium sulfate (anhydrous) g-- 100 Acetic acid (glacial)ml 20 Sodium acetate (crystalline) g-.. 10.5 H2O to 1 liter. Kelzan Fg-- 5 Manucol SA/LM g-.. 25

Viscosity, 8,300 centipoises. pH 4.0.

Hardener:

Thymol 1 m1 5 Glutaraldehyde (25 percent) ml 160 Sodium sulfate(anhydrous) g-- 100 H2O to 1 liter. Kelzan F g 4 Manucol SA/LM g-- 24Viscosity 10,800 centipoises. pH 4.0.

15 Neutralizer:

Thymol 1 ml 5 Hydroxylamine sulfate g 20 Acetic acid (glacial) ml 10NaOH g 10 H2O to 1 liter. Kelzan F g-- Manucol SA/ LM g 30 Viscosity10,300 centipoises. pH 6.0. Color developer:

Thymol 1 ml 5 Quadrafos g 5 Benzyl alcohol ml 15 T-butylamine boranetablet 1/2 Sodium sulte g 7.5 Sodium phosphate (tribasic) g-- 40 Sodiumbromide g 0.9 KI (0.1% solution) ml 24 Citrazinic acid g-- 3.6 CD-3 g 13NaOH g 7.5 H2O to 1 liter. Kelzan F g 1.5 Manucol SA/LM g 60 Viscosity8,300 centipoises. pH 12.3. Second stop bath:

Thymol 1 ml 5 Sodium metabisultite g-- 40 H2O to 1 liter. Kelzan F g 5Manucol SA/LM g-- Viscosity 3,300 centipoises. pH 4.0. Bleach:

Thymol 1 ml 5 Sodium bromide g 26 Sodium ferrocyanide, decahydrate g 180Potassium persulfate g 51 Sodium phosphate, dibasic (anhydrous) g 12.5Carbowax 1540 (50 percent) ml 6 H2O to 1 liter. Kelzan F g 3 ManucolSA/LM g 25 Viscosity 8,600 centipoises. pH 7.8. Fixer:

Thymol 1 ml 5 Sodium thiosulfate, pentahydrate g 250 Ammonium sulfate g50 Sodium sulte g 10 H2O to l liter. Kelzan F g 3 Manucol SA/LM g 25Viscosity 6,600 centipoises. pH 7.6.

Wash stabilizer:

Thymol1 ml 5 Formalin ml 10 EDTA (tetrasodium salt) grams 10 H2O to 1liter. Kelzan F grams 4 Manucol SA/LM ..do 30 Viscosity SA&LM 10,800centipoises. pH 10.0

1 0.1% solution.

All pH and viscosity values are measured at 80 F. and the viscositiesare measured with a Brookfield viscometer.

The viscous processing solutions are applied to the film with athickness of about 0.02 inch by extruding them through a nozzlepositioned tangential to the film and are removed after the specifieddwell time by a squeegee. The film speed is set at ve feet per minute.

16 The following Eastman Kodak Ektachrome aerial type film strips areexposed through a 21step wedge as follows:

Type Exposure conditions 8442 0.01 sees., Eastman Type 1b Sensitometer,5,900 K. lter.

8443 0.1 secs., Eastman Type 1b sensitometer, 5,900 K., 2,200

K., B, G-15 lters.

SO-271- 0.1 secs., Eastman Type 1b sensitometer, no filter.

2448 0.04 secs., Eastman Type 1b sensitometer, 5,900 K. lter.

Processing conditions are:

Temperature, Viscous solution Dwell time F.

First developer 1 minute 100 First stop-. 30 seconds 100 Hardener 30seconds.-- 120 N eutralizer.. 15 seconds 120 Color develop 11/ minutes150 Second stop 30 seconds 120 Bleach 1 minute 4150 Fix 30 seconds 150Wash stabilizer 30 seconds 150 Approximately 80 square feet of iilm canbe processed per gallon of solution. The lms are uniformly processedwith no signs of emulsion damage. Upon completion of processing, thefilms are dried and sensitometrically evaluated. Good sensitometricresults are obtained.

EXAMPLE l2 A viscous negative color processing developer having thefollowing composition is prepared:

Viscosity 10,000 centipoises.

The stop bath, hardener, bleach, fixer and wash sta bilizer have thesame compositions as in Example 11.

Eastman Kodak Kodacolor X lm is exposed through a 21-step tablet on anEG&G Mark VI sensitometer for 1A00 second. The iilm is then processed bysequentially applying a layer of viscous solution approximately 0.02inch thick for the dwell times and at the temperatures indicated below:

Temperature, Viscous solution Dwell time F.

Developer 6 minutes 85 Stop hath 30 Seconds 85 Hardener-. 30 seconds 120Bleach 45 seconds 150 Fixer 30 seconds 150 Wash stabilizer 30 seconds150 The film is uniformly processed without damage to the photosensitiveemulsion and good sensitometric results are obtained.

What is claimed is:

1. In the color processing of an exposed photosensitive mediumcontaining color-forming material wherein said color-forming material isprocessed into image form including at least the steps of hardening theemulsion and developing, the improvement which comprises:

(a) first developing a photographic image in said medium by treatmentwith a photographic developer therefore; and,

(b) subsequently hardening the emulsion of said medium to be stable towater at a temperature of at least about F.

2. An improvement of claim 1 wherein the emulsion comprises gelatin andwherein said gelatin is hardened with an aldehyde hardener therefor.

3. An improvement of claim 2 wherein said aldehyde hardener comprises adialdehyde hardener.

4. An improvement of claim 3 wherein the gelatin emulsion is hardened tobe stable to water at a temperature of at least about 180 F.

5. An improvement of claim 4 wherein said photographic developercomprises an aqueous alkaline developer and said first developingresults in a black and white photographic image.

6. An improvement of claim 5 wherein said dialdehyde hardener comprisesglutaraldehyde.

7. A method for rapidly processing an exposed color reversalphotosensitive emulsion, comprising:

(a) rst developing a black and white negative image in said emulsion bytreatment with a photographic developer therefor at a temperature belowthat at which emulsion damage occurs;

(b) subsequently hardening the emulsion to be stable to water at atemperature of at least about 140 F.; and thereafter,

(c) color processing said emulsion at an elevated temperature above thefirst development temperature.

8. A method of claim 7 wherein color development is carried out at atemperature of at least about 100 F.

9. A method of claim 7 wherein color development is carried out at atemperature in the range of from about 140 F. t0 about 155 F.

10. A method of claim 9 wherein said photographic developer comprises anaqueous alkaline photographic developer.

11. A method of claim 10 wherein said hardening step (b) comprises:

(a) acidifying the emulsion;

(b) contacting said aciditied emulsion with an aldehyde hardenertherefor; and,

(c) removing substantially all free aldehyde from said emulsion prior tocolor processing.

12. A method of claim 11 wherein said aqueous alkaline photographicdeveloper contains methylhydroquinone.

13. A method of claim 12 wherein said aldehyde hardener comprises adialdehyde containing a linear chain of 2-3 carbon atoms linking the twoaldehyde groups.

14. The method of claim 13 wherein said aqueous alkaline development isconducted at a temperature in the range of from about 70 F. to about 80F. and said developer has a pH in the range of from about 9.5 to about10.5.

15. A method of claim 14 wherein said dialdehyde hardener comprisesglutaraldehyde.

16. A method of claim 15 wherein said hardening step is conducted bycontacting said emulsion with said glutaraldehyde at a temperature offrom about 90 F. to about 110 F. for a period of from about 10 to about120 seconds.

17. A method of claim 16 wherein the emulsion acidication step isconducted by contacting said emulsion with an aqueous solution of aphotographically-acceptable acid, the pH of said solution being in therange of from about 4 to about 6.

18. A method of claim 17 wherein said acid comprises acetic acid.

19. A method of claim 18 wherein said emulsion comprises gelatin andsaid acid solution includes a gelatin swell-suppressing agent.

20. A method of claim 19 wherein said gelatin swellsuppressing agentcomprises an alkali metal sulfate or ammonium sulfate.

21. A method of claim 19 said gelatin swell-suppressing agent comprisessodium sulfate.

22. A method of claim 21 wherein substantially all of the free aldehydeis removed after hardening by contacting the emulsion with a solution ofan aldehyde-reactive 18 amine at a temperature in the range of fromabout 70 F. to about 145 F. and having a pH in the range of from about 3to about 6.

23. A method of claim 22 wherein said color processing includes thefollowing steps:

(a) color-developing the emulsion;

(b) clearing the emulsion of color developer;

(c) bleaching out the metallic silver deposits;

(d) fixing the silver halide of the emulsion; and,

(e) stabilizing the emulsion.

24. A method of claim 7 wherein the emulsion is hardened to be stable towater at a temperature of at least about 180 F.

2S. A method of claim 24 wherein color development is carried out at attemperature in the range of from about 140 F. to about 155 F.

26. In the processing of an exposed, negative, color, photosensitiveemulsion including the steps of hardening said emulsion andcolor-developing, the improvement comprising:

(a) first color developing the latent image in said emulsion bytreatment with a color developer; and,

(b) subsequently hardening said emulsion to be stable to water at atemperature of at least about 140 F.

27. An improvement of claim 26 wherein said emulsion is hardened bycontacting it with a solution of a dialdehyde hardener.

28. An improvement of claim 27 wherein said dialdehyde hardenercomprises glutaraldehyde.

29. An improvement of claim 28 wherein said emulsion is hardened to bestable to water at a temperature of at least about 180 F.

30. In the reversal color processing of an exposed photo sensitivemedium including at least the process steps of hardening the emulsion,developing a black and white image, and subsequently developing a colorreversal image, the improvement which comprises hardening the emulsionto be stable to water at a temperature of at least about 140 F. afterdeveloping the black and white image but prior to developing the colorreversal image.

31. An improvement of claim 30 wherein said emulsion is hardened to bestable to water at a temperature of at least about 180 F.

32. An improvement of claim 31 wherein color development is carried outat a temperature of at least about F.

33. An improvement of claim 31 wherein color development is carried outat a temperature in the range of from about F. to about 155 F.

34. An improvement of claim 33 wherein said emulsion is hardened bycontacting it with a solution of a dialdehyde hardener.

35. An improvement of claim 34 wherein said dialdehyde hardenetcomprises glutaraldehyde.

36. An improvement of claim 1 including the use of at least one viscousprocessing solution.

37. An improvement of claim 36 wherein said viscous processing solutioncomprises a color developer solution.

38. An improvement of claim 37 wherein said viscous processing solutioncontains a thickener selected from the group consisting of natural gum,guar bean gum, xanthan gum, sodium alginate, sodium polystyrenesulfonate, and combinations of these.

39. An improvement of claim 36 wherein all the solutions are viscousprocessing solutions.

40. An improvement of claim 26 including the use of at least one viscousprocessing solution.

41. In the color processing of an exposed photo-sensitive mediumcontaining color-forming material wherein said color-forming material isprocessed into image form including at least the steps of hardening theemulsion and developing, the improvement which comprises:

(a) rst developing a photographic image in said medium by treatment witha photographic developer therefor; and, l

19 (b) subsequently hardening the emulsion of said rnedium to be stableto rapid processing wherein at least one of the steps after hardening iscarried out at a temperature of at least about 100 F.

References Cited UNITED STATES PATENTS 26 2,359,217 9/ 1944 Hollander96-111 3,232,761 2/1966 Allen 96-111 3,140,177 7/1964 Welch 96-111NORMAN G. TORCHIN, Primary Examiner I. L. GOODROW, Assistant ExaminerU.S. Cl. X.R. 96-111

